A failure to scp the app makes AppScale stuck

[Navraj Chohan]

In a 4 node EC2 configuration with cassandra as the datastore, an application was uploaded, but the scp of the application failed. The application is started, but because the application is not in the folder of /var/apps/appname/app it never starts. I'm assuming that from this point god keeps trying to start the application. We need some method to check if the files were successfully copied over before starting up the application. Also, in the case the application is bad, we run into a similar problem. Therefore we need to first check that the application starts without terminating before proceeding.